diff options
| author | Alexander Graf <agraf@suse.de> | 2017-01-16 12:46:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-26 08:24:44 +0100 |
| commit | 776c2b2d165dc64397f3f9b39839920a08578e8f (patch) | |
| tree | 93b234486354a473c8b48d91c6b328a41ebee49e /arch/arm64 | |
| parent | 962957889d74c161d797dbf418d8d7ded241aaa1 (diff) | |
arm64: Fix swiotlb fallback allocation
commit 524dabe1c68e0bca25ce7b108099e5d89472a101 upstream.
Commit b67a8b29df introduced logic to skip swiotlb allocation when all memory
is DMA accessible anyway.
While this is a great idea, __dma_alloc still calls swiotlb code unconditionally
to allocate memory when there is no CMA memory available. The swiotlb code is
called to ensure that we at least try get_free_pages().
Without initialization, swiotlb allocation code tries to access io_tlb_list
which is NULL. That results in a stack trace like this:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
[...]
[<ffff00000845b908>] swiotlb_tbl_map_single+0xd0/0x2b0
[<ffff00000845be94>] swiotlb_alloc_coherent+0x10c/0x198
[<ffff000008099dc0>] __dma_alloc+0x68/0x1a8
[<ffff000000a1b410>] drm_gem_cma_create+0x98/0x108 [drm]
[<ffff000000abcaac>] drm_fbdev_cma_create_with_funcs+0xbc/0x368 [drm_kms_helper]
[<ffff000000abcd84>] drm_fbdev_cma_create+0x2c/0x40 [drm_kms_helper]
[<ffff000000abc040>] drm_fb_helper_initial_config+0x238/0x410 [drm_kms_helper]
[<ffff000000abce88>] drm_fbdev_cma_init_with_funcs+0x98/0x160 [drm_kms_helper]
[<ffff000000abcf90>] drm_fbdev_cma_init+0x40/0x58 [drm_kms_helper]
[<ffff000000b47980>] vc4_kms_load+0x90/0xf0 [vc4]
[<ffff000000b46a94>] vc4_drm_bind+0xec/0x168 [vc4]
[...]
Thankfully swiotlb code just learned how to not do allocations with the FORCE_NO
option. This patch configures the swiotlb code to use that if we decide not to
initialize the swiotlb framework.
Fixes: b67a8b29df ("arm64: mm: only initialize swiotlb when necessary")
Signed-off-by: Alexander Graf <agraf@suse.de>
CC: Jisheng Zhang <jszhang@marvell.com>
CC: Geert Uytterhoeven <geert+renesas@glider.be>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/mm/init.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 212c4d1e2f26..59bd3d47647b 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -403,6 +403,8 @@ void __init mem_init(void) { if (swiotlb_force || max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT)) swiotlb_init(1); + else + swiotlb_force = SWIOTLB_NO_FORCE; set_max_mapnr(pfn_to_page(max_pfn) - mem_map); |